It is common for patients to seek the advice of a physician when experiencing discomfort. However, patients seldom present physicians with a diagnosis already made; instead, they present one or more symptoms. Selecting the most probable diagnosis from a list of alternatives (hypotheses) is a process called differential diagnosis. Certain signs or symptoms can suggest a specific disease etiology. However, patients typically present physicians with clinical symptoms that are confounding, which make diagnosis based on only the symptoms very difficult. The physician has the daunting task of determining which of a number of principal etiologies is responsible for the discomfort the patient is experiencing. This is also important because selecting a specific diagnosis has implications for the treatment plan and therapy. The symptoms prompt the physician to gather information through history, physical examination and, most importantly, diagnostic tests identifying clinical findings that suggest explanations for the symptom(s).
Thus, diagnostic tests, both performed at a laboratory and at the point-of-care (POC), are an integral part of the health care system. Such tests play a central role in all aspects of patient care, including disease-diagnosis, monitoring progression of therapy, as well as screening for health and infection. Molecular diagnostics tests (such as in vitro diagnostic (IVD) tests) are especially useful, as they pinpoint the exact cause of a particular clinical manifestation and thus help the physician to make a diagnosis and then prescribe the right treatment and therapy.
Currently, the diagnostic testing process is very tedious, time-consuming, cumbersome, and slow. This is because a number of different tests often have to be performed for a given symptom and each of these tests is performed individually. Moreover, because laboratories are constantly updating and adding new tests that facilitate medical diagnosis, physicians regularly confront dilemmas when ordering and interpreting these tests. Over the last two decades, the total number of clinical tests and the types of different tests available to physicians has grown exponentially. These advances in modern clinical laboratory medicine, though enormously helpful, also create new problems. These tests are often not user friendly, and increase costs in an already heavily burdened health care system. In common practice, physicians also complain about the delay in the processing of tests at the laboratories thus delaying accurate patient diagnosis. Additionally, many tests are not available at all, are available at only one or two testing sites/laboratories, or are known only to specialists.
Effective management of diseases requires an awareness of the full spectrum of etiologies and their possible complications. Sometimes the initially chosen set of tests present results that are not clear, which precludes an accurate diagnosis. The nature and relatively non-specific symptoms of the disease can make a proper diagnosis challenging. In such cases more tests are performed, which are run in an iterative and sequential fashion. Thus, testing slows down the entire process of patient care and treatment, which is costly, and is detrimental to the patient's health and treatment plans.